In many manufacturing environments, machines, manufacturing equipment and other such systems are used to produce particular goods or components for goods. These machines most often are attended by a machine operator who actually controls the machine operation. During normal operation the machine operator generally can operate the machine without any help.
However, in the instances where the machine experiences a problem or there is insufficient system control, the operator must then solve the problem or contact others for help. With the lost productivity and opportunity cost of some of the machines available today, it is extremely costly to have the machine down until a service engineer can be dispatched to the site of the malfunctioning machine. Therefore, it is beneficial to reduce the amount of machine down time to a minimum and to lessen the need for reliance on outside service representatives to make service calls.
Likewise, actions to update, change, correct or otherwise modify the machine can result in unwanted down time. Moreover, it can be very expensive to dispatch a service engineer to perform the update, change or modification to the machine.
Thus, heretofore an unaddressed need exists in the industry to address the aforementioned deficiencies quickly and efficiently. This need is particularly pronounced for dispensers of foam material with foam-in-bag dispensing systems being in particular need for monitoring and effective control. The ability to control manufacturing devices such as foam-in-bag dispensing systems, which feature a lot of simultaneously operating systems and the potential for any one of those sub-systems to have a problem or go out of a preferred operating range, is also problematic in the associated industry. Further, the control units used on manufacturing device such as foam-in-bag dispensers are problematic in the sense of not providing an efficient control panel with readily and accurately manipulated control buttons.
For example, over the years a variety of material dispensers have been developed including those directed at dispensing foamable material such as polyurethane foam which involves mixing certain chemicals together to form a polymeric product while at the same time generating gases such as carbon dioxide and water vapor. If those chemicals are selected so that they harden following the generation of the carbon dioxide and water vapor, they can be used to form “hardened” (e.g., a cushionable quality in a proper fully expanded state) polymer foams in which the mechanical foaming action is caused by the gaseous carbon dioxide and water vapor leaving the mixture.
In particular techniques, synthetic foams such as polyurethane foam are formed from liquid organic resins and polyisocyanates in a mixing chamber (e.g., a liquid form of isocyanate, which is often referenced in the industry as chemical “A”, and a multi-component liquid blend called polyurethane resin, which is often referenced in the industry as chemical “B”). The mixture can be dispensed into a receptacle, such as a package or a foam-in-place bag (see e.g., U.S. Pat. Nos. 4,674,268, 4,800,708 and 4,854,109), where it reacts to form a polyurethane foam.
A particular problem associated with certain foams is that, once mixed, the organic resin and polyisocyanate generally react relatively rapidly so that their foam product tends to accumulate in all openings through which the material passes. Furthermore, some of the more useful polymers that form foamable compositions are adhesive. As a result, the foamable composition, which is often dispensed as a somewhat viscous liquid, tends to adhere to objects that it strikes and then harden in place. Many of these adhesive foamable compositions tenaciously stick to the contact surface making removal particularly difficult. Solvents are often utilized in an effort to remove the hardened foamable composition from surfaces not intended for contact, but even with solvents (particularly when considering the limitations on the type of solvents suited for worker contact or exposure) this can prove to be a difficult task. The undesirable adhesion can take place in the general region where chemicals A and B first come in contact (e.g., a dispenser mixing chamber) or an upstream location, as in individual injection ports, in light of the expansive quality of the mix, or downstream as in the outlet tip of the dispenser or, in actuality, anywhere in the vicinity of the dispensing device upon, for instance, a misaiming, misapplication or leak (e.g., a foam bag with leaking end or edge seals). For example, a “foam-up” in a foam-in-bag dispenser, where the mixed material is not properly confined within a receiving bag, can lead to foam hardening in every nook and cranny of the dispensing system making complete removal not reasonably attainable, particularly when considering the configuration of the prior art systems.
Because of this adhesion characteristic, steps have been taken in the prior art to attempt to preclude contact of chemicals A and B at non-desired locations as well as precluding the passage of mixed chemicals A/B from traveling to undesired areas or from dwelling in areas such as the discharge passageway for aiming the A/B chemical mixture. Examples of dispensing systems for such foamable compositions and their operation are described in U.S. Pat. Nos. 4,568,003 and 4,898,327. As set forth in both of these patents, in a typical dispensing cartridge, the mixing chamber for the foam precursors is a cylindrical core having a bore that extends longitudinally there through. The core is typically formed from a fluorinated hydrocarbon polymer such as polytetrafluoroethylene (“PTFE” or “TFE”). Polymers of this type are widely available from several companies, and one of the most familiar designations for such materials is “Teflon”, the trademark used by DuPont for such materials.
Teflon material and many of the related polymers have the ability to “cold flow” or “creep”. This cold flow distortion of the Teflon is both beneficial (e.g., allowing for the conformance of material about surfaces intended to be sealed off) and a cause of several problems, including the potential for the loss of the fit between the bore and the valving rod as well as the fit between the openings (e.g., ports) through which the separate precursors enter the bore for mixing and then dispensing. In many of the prior art systems utilizing Teflon, the Teflon core is fitted in the cartridge under a certain degree of compression in order to help prevent leaks in a manner in which a gasket is fitted under stress for the same purpose. This compression also encourages the Teflon to creep into any gaps or other openings that may be adjacent to it which can be either good or bad depending on the movement and what surface is being contacted or discontinued from contact in view of the cold flow.
Under these prior art systems, however, over time the sealing quality of the core is lost at least to some extent allowing for an initial build up of the hardenable material which can lead to a cycle of seal degradation and worsening build up of hardened material. This in turn can lead to a variety of problems including the partial blockage of chemical inlet ports so as to alter the desired flow mix and degrade the quality of foam produced. In other words, in typical injection cartridges the separate foam precursors enter the bore through separate entry ports and polyurethane foam tends to build up at the area at which the precursor exits the port and enters the mixing chamber. Such buildups cause spraying in the output stream, and dispensing of the mixture in an improper ratio. The build up of hardened material can also lead to partial blockage of the dispenser's exit outlet causing a misaiming of the dispensed flow into contact with an undesirable surface (e.g., the operator or various nooks and crannies in the dispenser). Another source of improper foam output is found in a partially or completely blocked off dispenser outlet tip that, if occurs, can lead the foam spray in undesirable areas or system shutdown if the outlet becomes so blocked as to preclude output. A variety of prior art systems have been developed in an effort avoid tip blockage, particularly in automated systems, as in foam-in-bag systems, which impose additional requirements due to the typical high usage level and the less ready access to the tip as compared to a hand-held dispenser (although the present invention can also be utilized in such environments such as in the control of other sub-systems (e.g., chemical pumping operation)). The prior art systems include, for example, porous tips with solvent flush systems. However, over time these tips tend to load up with hardened foam and eventually become ineffective.
The build of hardened/adhesive material over time can lead to additional problems such as the valve rod and even a purge only rod, becoming so adhered within its region of reciprocal travel that either the driver mechanism is unable to move the rod (leading to an oft seen shut down signal generation in many common prior art systems) or a component along the drive train breaks off which is often the annular recessed valve rod engagement location relative to some prior art designs or simply wears out as in gear slippage.
The above described dispensing device has utility in the packing industry such as hand held dispensers which can be used, for instance, to fill in cavities between an object being packed and a container (e.g., cardboard box) in which the object is positioned. Manufacturers who produce large quantities of a particular product also achieve efficiencies in utilizing automated dispensing devices which provide for automated packaging filling such as by controlled filling of a box conveyed past the dispenser (e.g., spraying into a box having a protective covering over the product), intermediate automated formation of molded foam bodies, or the automatic fabrication of foam filled bags, which can also be preformed or placed in a desired location prior to full expansion of the foam whereupon the bag conforms in shape to the packed object as it expands out to its final shape.
With dispensing devices like the hand held and foam-in-bag dispensing apparatus described above, there is also a need to provide the chemical(s) (e.g., chemicals “A” and “B”) from their respective sources (typically a large container such as a 55 gallon container for each respective chemical) in the desired state (e.g., the desired flow rate, volume, pressure, and temperature). Thus, even with a brand new dispenser, there are additional requirements involved in attempting to achieve a desired foam product. Under the present state of the art a variety of pumping techniques have arisen which feature individual pumps designed for insertion into the chemical source containers coupled with a controller provided in an effort to maintain the desired flow rate characteristics through monitoring pump characteristics. The individual in “barrel” pumps typically feature a tachometer used in association with a controller attempting to maintain the desired flow rate of chemical to the dispenser by adjustment in pump output. The tachometers used in the prior art are relatively sensitive equipment and prone to breakdowns and thus, while usable under systems of the present invention, are not the preferred choice in most instances. Also, under many prior art systems, particularly those having in “barrel” pump motors with associated pressure transducers and tachometers, and temperate monitors to maintain a desired chemical pump speed/pressure level electronic circuitry as in electrical drivers are placed far away from the dispensing location requiring electrical leads to extend to/from a dispensing stand with its own electrical control system to an electrical console sub-system or the like with control logic, driver circuitry, etc. Under this prior art arrangement there was generated a large amount of electromagnetic energy along these lines and in the pump and console regions which were not or only minimally protected from allowing electromagnetic output into the environment. Thus, many prior art systems failed to have satisfactory “CE” levels and failed the CE European certificates program for electromagnetic noise levels.
In an effort to address the injection of chemicals into the mixing chamber at the desired temperature(s) there has been developed heater systems positioned in the chemical conduits extending between the chemical supply and the dispenser, these heaters include temperature sensors (thermisters) and are adjusted (rather crudely) in an effort to achieve the desired temperature in the chemical leaving the feed line or conduit. Reference is made to, for example, U.S. Pat. Nos. 2,890,836 and 3,976,230.
As noted above, in the packaging industry, a variety of devices have been developed to automatically fabricate foam filled bags for use as protective inserts in packages. Some examples of these foam-in-bag fabrication devices can be seen in U.S. Pat. Nos. 5,376,219; 4,854,109; 4,983,007; 5,139,151; 5,575,435; 5,679,208; 5,727,370 and 6,311,740. In addition to the common occurrence of foam dispenser system lock up, cleaning downtime requirements, poor mix performance in prior art foam-in-bag systems, a dispenser system featuring an apparatus for automatically fabricating foam filled bags introduces some added complexity and operator problems. For example, an automated foam-in-bag system adds additional complexity relative to film supply, film tracking and tensioning, bag sealing/cutting (e.g., from the stand point of a proper temperature cutter/sealer or proper cutter/sealer positioning and compression levels relative to the bag being formed), bag venting, film feed blockage. Thus, in addition to the variety of problems associated with the prior art attempts to provide chemicals to the dispenser in the proper rate, keeping the dispenser cartridge operational, and feeding film properly (e.g., positioning and tension), the prior art foam-in-bag systems also represent a particular source of additional problems for the operators. Additional problems include, for example, attempting to understand and operate a highly complicated, multi-component assembly for feeding, sealing, tracking and/or supplying film to the bag formation area; high breakdown or misadjustment occurrence due to the number of components and complex arrangement of the components; poor quality bag formation, often associated with poor film tracking performance, difficulty in achieving proper bag seals and cuts, particularly when taking into consideration the degrading and contamination of the often used heater wires due to, for example, foam build up and the inability to accurately monitor current heated wire temperature application, difficulty in formation and maintaining clear bag vent holes, as well as the inevitable foam contamination derivable from a number of sources such as the dispenser and/or bag leakage, and clean up requirements in general and when foam spillage occurs.
Many prior art foam-in-bag systems and other automated dispending systems have shown in the field to have high service requirements due to, for example, breakdowns and rapid supply usage requirements (e.g., film, solvent, precursor chemicals, etc.). There is thus a great deal of servicing associated with prior art systems as in problem solving and in maintaining adequate supply levels. The prior art systems suffer from the problem of difficult and often non-adequate servicing which can be operator or service representative induced (e.g., failing to monitor own supply levels (e.g., solvent supply) or anticipating level of usage, or difficulty in responding timely to service requests which are often on an emergency or rush basis as any down time can be highly disruptive to an operator in timely meeting orders). In addition, foam-in-bag system, when in operation can require rapid system manipulation and changes as in dispenser timing, bag size adjustments, menu scrolling etc. (e.g., in some foam-in-bag system settings there is required rapid action on the part of the operator to avoid having a filled bag harden before being properly positioned).
As can be seen there are numerous potential areas that can create problems in the field of dispensing, and this type of manufacturing equipment has a great need for close monitoring to preempt potential problems, spot problems when they arise, and take appropriate action to prevent further system problems. Accordingly, foam-in-bag dispensing systems and the like are illustrative of systems which work well with the present inventive subject matter directed at a control system for one or more of the various subsystems, and a system and method for providing remote monitoring of a manufacturing device including, preferably, an interfacing relationship with the operational control system as well as enhanced button control as explained below.